An in-house video for Air NZ staff has been publicly released today, explaining the Dreamliner engine issues that have disrupted thousands of travelers this week.

The two minute video was designed for Air New Zealand's 12,000 staff, and explains why tests on the Rolls Royce engines on Boeing-787 Dreamliner planes have been enforced globally.

Around 6500 Air NZ passengers have, and will, have their flights disrupted into next week.

In layman terms, as the video describes it, the checks are looking for cracks in the blades of the compressor section of the jet engine.

"If the engines fail, they will be removed and sent to Singapore to the Rolls Royce facility for repair," Air NZ engineer Logan Horrell says.

Operators have been ordered to do inspections on a specific part of the compressor in the Rolls Royce engine much earlier than expected - at 300 cycles instead of 2000 cycles.

A single cycle in aviation terminology is when a plane takes off and lands.

Asked by Air NZ chief operating officer Bruce Parton whether these Rolls Royce engines are " lemons, or are they alright" Mr Horrell assures this is normal practice.

"No, this is a normal engine process for any engine type. These engines go through teething issues and once we repair the engines we expect them to be just as reliable as any other engine," Horrell says.

Mr Horrell ends the video by assuring viewers that the engines were safe, and the tests currently being enforced were "conservative".